Improvement in trunk-engines



UNITED STATES PATENT OEEICE.

JOHN B. R()OT, OF NEW YORK, N. Y.

IMPROVEMENT IN TRUNK-ENGINES.

Speciiication forming part-of Letters Patent N0. 57,190, dated August14, 1866.

To all 'whom it may concern Beit known that I, JOHN B. ROOT, of thecity, county, and State of New York, have invented a new and usefulImprovement in Trunk-Engines; and I do hereby declare that the followingis a full7 clear, and exact de scription of the same, reference beinghad to the accompanying drawing, forming part of this specification,said drawing representing a central longitudinal vertical section of atrunk-en gine with the improvement applied.

One ofthe difficulties encountered in trunkengines of large size hasbeen that of preserving a tight packing in the very large stuffingboxesemployed around the trunk.

The object of this invention is to obviate this difculty; and to thisend the invention consists in dispensing with stung-boxes for thepacking of the trunks by the use of eX- pandingpacking-ringssubstantially like those used for piston-packing inserted into groovesin the trunk and working in cylindrical guides attached to thecylinder-heads.

To enable others skilled in the art to apply my invention to use. I willproceed to describe it with reference to the drawing. A

A is the cylinder of the engine. B is the piston surrounding andattached to the trunk which extends through both cylinder-heads andworks in two cylindrical guides, F F, attached to the cylinder-heads DD. These guides are concentric with the cylinder, and each of a lengthsomewhat 0^reater than the stroke of the piston, and areqbored out trulyand smoothly.

E E are the expanding packing-rings, of metal, which constitute theprincipal feature of my invention, fitted into circumferential grooves cc, which are formed in the exterior of the trunk in such positions thatduring the stroke of the engine they will work within the guides F F,one within one and the other within the other ot' the said guides. Thesepacking-rings may be of any known or suitable construction, and bepressed out to work steam-tight within the guides either by means ofsprings or by the pressure of the steam,

which passes from the cylinder between the trunk and guides and entersthe grooves a a.; but I prefer to use rings ot' the construction whichis the subject-matter of my application for Letters Patent IallowedFebruary 8, 1866. These rings, fitting and working steam-tight withinthe cylindrical bores ot' the guides F F, effectually prevent any steamfrom escaping from the cylinder between the trunk and the guides beyondthe said rings.

A similar packing-rin g and cylindrical guide may be used intrunk-engines in which the trunk passes through one cylinder-head only.

One advantage of arranging the packingrings in grooves around theexterior of the trunk over their arrangement in stufling-boxes attachedto the cylinders consists in their permitting the use oi' longercylindrical guides F F with a given length of trunk, and therebyenabling the engine with a given length of stroke and guide to be madeconsiderably shorter. In explanation of this, let it be supposed thatthe rings were arranged near the outer ends ot the cylindrical guides.The trunk would then have to be long enough to remain within the ringswhen the. piston was at the end of the stroke farthest from either ring.

Another advantage of this arrangement of metallic packing rings consistsin the simplicity of construction provided for compared with theinsertion of such rings into guides of a similar character tostuffing-boxes, such rings in the latter case requiring glands and boltsin the ends ofthe guides.

I do not confine myself to the particular construction of thepacking-rings herein specified; but

What I claim as my invention, and desire to secure by Letters Patent,is-

rIhe arrangement of the packing-rings within the trunk, in combinationwith the cylindrical guides F F, attached to the cylinder, substantiallyas and for the purpose herein specified.

JOHN B. ROOT.

Witnesses:

J. W. Cocinas, A. LE CLERC.

